The need for, and use of, communication systems to communicate therethrough has become an endemic and necessary, part of modem society.
As a result of advancements in communication technologies, new types of communication systems, as well as improvements to existing communication systems have been permitted. Amongst the advancements in communication technologies are advancements in digital communication techniques. When digital communication techniques are used, data that is to be communicated is digitized. And, the digitized data, so-formed, is formatted in a selected manner, prior to communication thereof. Formatting of the digital data typically includes packetizing the data into data packets.
Generally, standardized protocols are utilized by which to format the data into packets. Communication devices that are constructed to be operable pursuant to send or to receive data formatted pursuant to a particular protocol are able, as appropriate, to send or to receive such data as long as the data is formatted according to the appropriate protocol.
More than one formatting protocol is sometimes used when communicating data. That is to say, multiple levels, or layers, of formatting of the digitized data are sometimes provided. A communication device, used to communicate data can be represented in logical-layer form. Such a representation including layers at which formatting is applied to, or removed from, digitized data.
A user datagram protocol (UDP), or UDP protocol, is an exemplary protocol scheme that is widely utilized. UDP-formatted data is regularly communicated, for instance, in the effectuation of real-time communication services. Conventional UDP-formatting of data advantageously provides for sending-station-specified data rates. And, data packets delivered to a receiving station are delivered immediately to a receiving application irrespective of their order of arrival. In conventional UDP formatting, a checksum is used to verify UDP header and payload to data parts, thereby to effectuate validation of received data packets. Conventional UDP checksum protection provides protection for an entire payload portion of a UDP-formatted data packet or for none of the payload portion of the data packet.
Increasingly, radio communication systems utilize packet communication schemes in which packetized data is communicated upon an error prone air interface. A modified UDP formatting scheme, referred to as UDP-Lite, is sometimes utilized. UDP-Lite formatting is compatible with conventional, UDP formatting. But, UDP-Lite formatting provides improved functionality and flexibility, beneficial attributes for communications in a radio environment.
Various aspects of a UDP-Lite-formatted data packet differ with those of a conventional, UDP-formatted packet. For instance, the UDP length and checksum is replaced with a partial coverage length and partial checksum. Thereby, the data contained in the UDP-Lite data packet is separated into sensitive and nonsensitive sections. Pursuant to checksum calculations, when an error is detected in the sensitive part, the data packet is discarded. However, errors contained in the nonsensitive part of the data packet do not cause the data packet to be discarded. Instead, the data packet is forwarded for further processing of the data irrespective of whether the nonsensitive part contains errors.
While the UDP-Lite formatting advantageously forms sensitive and nonsensitive parts, if a lower-level layer, i.e., a layer beneath the UDP-Lite layer, fails to maintain the segregation between such parts, the advantages of such segregation are not provided.
While existing proposals have been set forth to maintain the segregation between the sensitive and nonsensitive parts of the UDP-Lite-formatted data packet, such existing proposals are relatively complex. And, such complexity is disadvantageous.
Generally, the UDP-Lite concept of insensitive data must be introduced to underlying layers so that the data is not subsequently checked for errors and discarded for containing errors.
Radio link protocol (RLP), is a lower-layer protocol used with a, e.g., cdma2000 traffic channel to support CDMA data services in a cdma2000 cellular, communication system. The RLP carries retransmission and re-sequencing procedures to reduce the frame error rate (FER) exhibited by a CDMA traffic channel. But, when formatting data pursuant to RLP, if the sensitivity of the UDP-Lite formatting is not maintained, the speed advantages provided by the nonsensitive part of the UDP-Lite-formatted data packet is not maintained. Other lower-layer formatting protocols also fail.
Therefore, a manner is required by which to maintain the sensitivity level of the UDP-Lite-formatted data when the data is subsequently formatted with a lower-level formatting protocol.
It is in light of this background information related to packet-based communications that the significant improvements of the present invention have evolved.